1. Field of the Invention
The present disclosure relates generally to smart card (“SC”) devices, and in particular but not exclusively, relates to a smart card device supporting both wireless and wired modes.
2. Description of the Related Art
Smart cards are plastic cards having an embedded integrated circuit (“IC”). That IC may be a logic circuit with its associated memories, a controller with its associated memories and software, or other type of intelligence. The IC of an SC is typically coupled to external pads, which allow the SC to communicate or perform transactions with external devices using some type of protocol. These external devices can include an SC reader, a host personal computer (“PC”), SC adapters and connectors, and the like.
The mechanical and electrical specifications of SCs are published by the International Standard Organization (“ISO”) and other organizations. For instance, the ISO 7816 protocol supports “wired” or “contact modes” for SCs. In the contact mode, the SC physically contacts with the SC reader such that both the SC and SC reader can communicate with each other. The ISO 7816 protocol uses a smart card that has external pads including at least a voltage supply pad (“VCC”), a ground pad (“GND”), a reset pad (“RST”), a clock pad (“CLK”), and an input/output pad (“I/O”). This ISO 7816 protocol is characterized by an answer-to reset (ATR) sequence when a power-on process or reset is applied in the smart card.
On the other hand, “wireless” or “contact-less” SC standards cover a variety of protocol types such as ISO 10536 (Close-coupled cards), ISO 14443 (Proximity cards), and ISO 15693 (Vicinity cards). Based on these contact-less standards, the contact-less SC and contact-less SC reader communicate with each other without physical connection by placing the SC closely to the SC reader. There is a small loop or antenna inside the contact-less SC, which makes electromagnetic induction contact with the SC reader. After the contact-less SC is placed closely to the contact-less SC reader, the contact-less SC will be activated by the electromagnetic field emitted from the SC reader.
In some implementations, the SC is used with the SC reader connected to the host computer through a USB cable. The USB standard has become firmly established and has gained wide acceptance in the PC marketplace. The USB standard was developed in response to a need for a standard interface that extends the concept of “plug and play” to devices external to a PC. It has enabled users to install and remove peripheral devices external to the PC without having to open the PC case or to remove power from the PC (e.g., without having to “reboot”). The USB standard provides a low-cost, high-performance serial interface that is easy to use and readily expandable, and is supported by an increasing number of SCs that are available in the marketplace. Based on the USB standard, the USB cable connected between the USB device and the host computer includes a voltage supply wire (“VBUS”), a ground wire (“GND”), a D-minus wire (“D−”), and a D-plus wire (“D+”).
A single mode smart card can separately support only one of a contact protocol (e.g., ISO 7816), contact-less protocol (e.g., ISO 14443), or the USB standard protocol. Furthermore, a dual mode smart card has the possibility to switch from an ISO 7816 protocol to a USB protocol or vice versa (such as disclosed in U.S. Pat. No. 6,439,464, assigned to the same assignee as the present application and incorporated by reference herein). The configuration of the smart card is chosen at power-on-reset depending on a hardware mode selection. A contact/contact-less dual mode smart card can operate in ISO 7816 mode or in ISO 14443 mode. Although there is a dual mode smart card available, such as the smart card supporting the USB protocol and the ISO 7816 protocol, or supporting the ISO 14443 protocol and ISO 7816 on the same chip, such kinds of smart cards can support only one mode at a time and not two modes simultaneously, and typically require turning power to the smart card on or off.